1. Regular exercise toughens your muscles and improves your overall strength.
2. Facing challenges head-on toughens your resolve and builds character.
3. The coach's strict training regimen toughens the players for competition.
4. The harsh environment in which they grew up toughens them for the realities of life.
5. Going through difficult experiences toughens you up and prepares you for future obstacles.
6. Eating a healthy diet rich in nutrients toughens your immune system.
7. The intense boot camp program toughens recruits both mentally and physically.
8. Learning to handle rejection and criticism toughens you for the ups and downs of a competitive industry.
9. The rigorous academic program at the university toughens students for the demands of the workforce.
10. Regular practice and perseverance toughen your skills and make you a better performer.